{
  "version": 2,
  "email": "eleonora.troja@nasa.gov",
  "submitter": "Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>",
  "circularId": 15437,
  "bibcode": "2013GCN.15437....1T",
  "subject": "GRB 131018B: RATIR Optical/NIR Observations",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>",
  "format": "text/plain",
  "body": "Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),\nAlexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.\nRicher (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska\n(UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen\nLittlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM),\nLeonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga\n(UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:\n\n\nWe observed the field of GRB 131018B (Vianello, et al., GCN 15357; \nZhang, et\nal., GCN 15360) with the Reionization and Transients Infrared Camera \n(RATIR;\nwww.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio\nAstronómico Nacional on Sierra San Pedro Mártir from 2013/10 20.09 to\n2013/10 20.27 UTC (33.94 to 38.36 hours after the GBM trigger),  and again\nthe next night from 2013/10 21.09 to 2013/10 21.27 UTC (57.93 to 62.34\nhours after the GBM trigger). We obtained a total of 2.8 hours exposure \nin the\nr and i bands and 1.3 hours exposure in the Z, Y, J, and H bands each \nnight.\n\nDuring the 1st night of observations, the position of the X-ray afterglow\nreported by D'Avanzo et al. (GCN 15361, 15431) falls at the edge of our \nfield\nof view in the Z and J bands. For a source within the Swift-XRT error \ncircle, in\ncomparison with 2MASS, we obtain the following upper limits (3-sigma):\n\n   Z   > 22.6\n   J    > 21.6\n\nDuring the 2nd night of observations, the XRT position was observed in all\nfilters. For a source within the Swift-XRT error circle, in comparison \nwith 2MASS\nand SDSS DR9, we obtain the following upper limits (3-sigma):\n\n   r   > 23.8\n   i   > 23.5\n   Z  > 22.8\n   Y  > 22.2\n   J   > 21.9\n   H  > 21.4\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro\nMártir.",
  "createdOn": 1383346634000,
  "editedOn": 1731005849262,
  "eventId": "GRB 131018B"
}